Second CNC table build, here we go again....

[Robin Hewitt]

When I started making one I got a piece of 4"x4"x10g aluminium box and made the gantry as the long axis. Across the front I bolted a linear rail, using the bolt from behind kind so the dust could not get inside the block via the bolt holes. I used 4 1/2" bolts and spacers so I could bolt everything from behind without crushing the box. I cut the box ends dead square. I inserted 1/2" square plates with 8mm steel nut inserts dead centre from either end. The gantry end plates had 4" x 4" recesses and an 8mm bolt hole. When I tightened that sucker up it became incredibly rigid. The gantry end plates got double round linear blocks running on 30mm round linear rails which held the assembly in place simply by being bloody heavy. I liked my design but it all went horribly wrong because the 5mm pulleys were such a crap fit on the 5mm belt. I lost heart.